Hydraulic motor



Nov. 26, 1940. I LIGHT 2,222,819

HYDRAULIC MOTOR Fil'ed Nov. 18, 19s".

lP/VEY I Patented New. 28,

8 Claims.

My invention relates to that class oi motors thatemploy a liquid as a driving medium, and an object of my invention, among others, is the production of a motor oi this type comprising a device which constitutes a positive adjustable stop to locate the extreme position 'of a piston moving in a cylinder in a hydraulic fluid circuit. It is accomplished with a cushioning action at the completion of the motion and with a common fluid inlet and outlet which permits the full force or the hydraulic fluid to be efiective upon the surface of the piston, immediately upon the commencement of return motion, thereby permitting quick acceleration of the return motion.

This control opens a new held of endeavor in the design of hydraulic machinery, for it makes possible the use of high speed, rapidly accelerating, reciprocating motion.

Difi'erent forms of structures embodying my invention and in the construction and use of which the objects herein set out, as well as others, may be attained, are illustrated in the accompanying drawing in which 1 Figure l is a view in lengthwise central section through the cylinder of a motor embodying my invention.

, Figure 2 is a similar view illustrating a modification.

Figure 3 is another similar view illustrating another modification, and

Figure 4 is still another similar view illustrating still another modification.

While my invention is not limited in its application for any particular purpose, it is especially adapted for use in cases where reciprocating movements oi mechanical parts are desired. In

such cases whenever a piston has been employed for the purpose various means havebeen used for preventing the piston from delivering blows when it reaches the ends of its paths in its reciprocating movements. My invention has to do with this feature and embodies novel means for preventing the delivery of such blows, this means for accomplishing the purpose being il= lustrated in the drawing herein in which the numeral 5 denotes a cylinderhaving a chamber ii, tubes i and 8 being attached to opposite ends of the cylinder for delivery and exhaust oi fluid thereto and therefrom. It will be understoodthat any suitable means common to this art and which are frequently employed will be used to control the alternate delivery and exhaust oi the liquid to and from each of the tubes. As such means is well understood a showing of it is omitted from the drawings herein. The cylinder chamber iii. The'recess is has a flared mouth it of -frusto-conical shape and opening into the chamber 6. i

The opposite end of the cylinder is closed by a plug it screw'threadedly engaged with an open- 15 ing into this end of the cylinder. The end oi this plug l6 which extends within the cylinder is shaped to form a space H between the plug and the cylinder wall with which the tube 8 communicates, in a satisfactory structureand as 20 shown herein, this space constituting an annular chamber. A conical recess 18 is formed in the end of the plug, as shown in Fig. 1 of the drawing.

A piston is is located for reciprocating move- .ment in the chamber s, a piston rod 28 'extend- 2B ing from the piston out through the plug I i, said rod being adapted for connection to any member to which reciprocating movement is to be imparted, such member not being shown herein as it is not essential to an understanding of the in- 30 ventlon which has to do with the movements of the piston.

The piston is tapered or of conical shape at opposite ends, the end 2! having the rod -20 projecting therefrom and the end 22 being free. V

The end 2i is shaped to correspond with the shape oi the mouth id ot the recess it in the plug 12, and the end 22 is shaped to correspond with the shape of the conical recess in the plug it.

The plugs H and It are provided with any 4; suitable means for'turning them to adjust their positions in the cylinder and consequently to adjust the positions of the mouth i5 and the recess 55, the angles of which and of the ends 2! and 22 need not be of any particular degree, as varias one angles of such parts will be fou d to produce satisfactory results.

In operation liquid being admitted to one end will force the piston to the opposite end of the cylinder and the liquid being exposed to a greater so surface-to-volume relationship in the recess is and its mouth 85 or in therecess E8, the movement of the piston is stopped without a blow at the end of its path of movement. In this opera tion a cushion is produced by the greater surface as sure on the whole surface of the piston from that just described.

In that form of the device shown in Fig. 2 the enlargement on the end of the cylinder is omitted,

' this cylinder 23 being of the same shape at both ends. The piston is of substantially the same shape as that hereinbefore described. The ends of the plugs 25-25 within the cylinder are shaped to create a space between said ends and the cylinder wall, in a satisfactory form such ends being reduced in size creating projections 26-2! forming annular chambers 28-49 at opposite ends of the cylinder and as shown in Fig. 2. The, plugs 24-45 as shown herein are screw threadedly engaged with the openings in the ends of the cylinder, as herelnbefore described, and suitable means for turning the plugs are provided. The tubes 1 and 8 communicate with the chambers 28- and 29 and the ends of the piston conform in shape to recesses 30 and 3i in the extensions 26 and 21 respectively. The operation of the piston is substantially the same as that in the device of Fig.

1, the cushioning of the piston and the retardation of its movements being effected in the same manner to avoid any hammering noises.

In that form of the device shown in Fig. 3, in which one end only of a cylinder 32 is shown, the plug 33 has a tapered projection 34 which is fitted to a tapered recess 35 in the piston 36. This is a reversal of the shapes of the piston and cylinder ends'from that hereinbefore described, but

- pensate for the space occupied by the piston rod.

The plug. 43 will also be correspondingly increased in size to fit the recess in the piston and will have an axial hole to receive the piston rod as shown.

In that form of the device shown in Fig. 4 the end of the piston is reduced in size toward its outer end by a stepped formation 38 on the end of the piston 39, one end of the cylinder only being shown in this view. The plug 40 has a'proiection 4| with a stepped recess 42. Tubes for supplyand exhaust are attached at each end of the cylinder, one of such tubes 31' only being shown. The opposite end of the piston will be correspondingly shaped, the piston being secured to and extending from the axial center as will be understood from an examination of Fig. 3 and the inner end of the plug being formedwith a recess to fit the end of the piston and with an axial hole'to receive the piston rod as hereinbeiore explained.

while light oil or even water may be used as a. driving medium to produce satisfactory results,

other typesof liquid may be employed. I

It should be noted that the spaces at the ends of the chambers in the cylinders are such as to effect pressure of the incoming liquid over the entire surfaces of the ends of the pistons as soon as the latter move away from the chamber ends enough to create any space whatsoever, thereby producing quick acceleratiom' It is here remarked that this cushioning eflect' begins to take place at the instant that the small end or point of the tapered member enters its recess, and this cushioning effect gradually increases in degree until it stops the movement of the piston at the end of its path of movement.

The adiustability of the piston ends or plugs is of material advantage in that the length of stroke of the piston and the cushioning eifect may be regulated to a nicety.

While the plugs have been shown herein as screw threaded to provide for adjustment of their positions, other constructions may be provided to obtain the results, this adjustment being a very important feature of the invention.

While the ends of the plugs extending into the cylinders are shown as shaped to create annular chambers, I contemplate other forms of the inner ends of the plugs to'create other shapes of recesses communicating with the inlet and exhaust tubes.

The motor is primarily designed for unusually rapid reciprocable movements of its piston and especially for obtaining maximum acceleration in the movements of the piston in the start of its reciprocatory movements. To accomplish this result, the coacting faces of the opposite ends of the piston and cylinder walls are so constructed that retardation in movement of the piston is effective substantially at its limit of reciprocatory movement and when moving into contact with the end of the cylinderor abutment therein. Also, it is to be noted that the approaching faces of the piston end and abutment with which the piston comes into direct contact are so angled that when the piston end is in contact with its abutment stop a part of the end of the piston remains in communication with the fluid passage so that the motive fluid is applied to the entire end of the piston at the commencement of movement of the piston away from its abutment stop. The motor has been especially designed for use in connection with a clamp device for the gripping of wires of different diameters. In the recipro-. catory movements of the piston, the ends thereof come into direct contact with abutment stops. It is therefore essential that these abutment stops be adjustable to accommodate the use of the motor in connection with a clamp for gripping wires of different diameters. The adjustment of tion with a stationary clamp member, while ad-' Justment of the abutment I} in the other end of the cylinder permits variations in the limits of opening movements of the movable clamp member away from the stationary clamp member to release the wire and guide the discharge thereof. I

Inaccordance with the provisions of the patent statutes I have described the principles ofoperation of my invention, together with the device which I now consider to represent the best embodiment thereof; but I desire to have it understood that the device shown is only illustrative and that'the invention" may be carried out by mounted for reciprocating movement therein,

said cylinder having a passage for both inlet and exhaust beyond the limit of reciprocating movement of a part of said piston, an abutment at the end of the cylinder for abutting contact by said piston, the approaching contacting faces of the piston and abutment having surfaces disposed at angles to the longitudinal axlsof the cylinder to produce a cushioning efiect and a stop to the movement of the piston in one direction whereby full pressure of a motive fluid is applied to a part of the piston when engaged with its abutment stop and to the entire outer end of the piston at the commencement of movement of the piston away from the abutment stop.

2. A hydraulic motor as specified in claim 1, wherein means is provided for adjustably mounting the abutment in the cylinder to vary the length of reciprocatory movement of the piston and the point in the cylinder where the piston comes to rest in contact with the abutment,

3. A hydraulic motor as specified in claim 1, wherein the contacting faces of the piston and abutment comprise a conical projection and 'a conical recess for the reception of said projection.

4. In a hydraulic motor, a cylinder, a piston mounted for reciprocating movements therein, said cylinder having a passage for both inlet and exhaust adjacent each end thereof beyond the limits of reciprocating movements of a part of the opposite ends of said piston, an abutment "at each end of the cylinder respectively for abutting contacts by opposite ends of said piston, the approaching contacting faces of the opposite ends of the piston and abutments having surfaces disrections whereby full pressure of a motive fluid is.

applied to the end of the piston that is engaged with its abutment stop and to the entire outer surface of said piston end engaged with said abutment stop at the commencement of movement of the piston away from the abutment stop.

5. A hydraulic motor as specified in claim 4, wherein one of said abutments has an axial bore therein, a rod carried by said piston reciprocably extending through said abutment bore and said abutment bore. having a portion thereof annular-= ment, surrounding the piston rod and in communication with the associated inlet and exhaust passage.

6. A hydraulic motor as specified in claim 4, wherein the inner end of each abutment carries a cylindrical extension terminating respectively inwardly of the adjacent inlet and exhaust passage and of less diameter than the internal didrical projection on the inner end of each abut-:

ment and a terminal conical extension carried by each projection traversing the adjacent inlet and exhaust passage, and the cooperating ends of said piston, each having an annularly reduced projection with a conical recess therein mating with the conical extension on the adjacent abutment end and cooperating therewith to form an annular. chamber surrounding the piston and abutment projections when the piston is engaged with an abutment, said chamber being in communication with the adjacent inlet and exhaust passage.

8. A hydraulic motor as specified in claim 4, wherein means is provided for adjustably mounting the abutment blocks in the cylinder to vary the length of reciprocatory movements of the piston and the points in the cylinder where the piston comes to rest in contact with its abutment.

GEORGE S. LIGHT.

. 1y enlarged to a chamber axially of the abut- 

